Given the following code in Oracle SQL Developer, please help me answer the question below:

The relational schemas are:

• Dept(DEPTNO, DNAME, LOC)

pk = {DEPTNO}

• Emp(EMPNO, ENAME, JOB, MGR, HIREDATE, SAL, COMM, DEPTNO)

pk = {EMPNO}

fk = {DEPTNO} references Dept(DEPTNO)

1. (Group By) Use SELECT statements to execute. Display the total number of employees in each year. Sort by year.

----------------------------------------------------------------------------------------------------------------------------

set termout on prompt Building demonstration tables. Please wait. set termout off set feedback off

ALTER SESSION SET NLS_LANGUAGE = AMERICAN; ALTER SESSION SET NLS_TERRITORY = AMERICA;

DROP TABLE EMP cascade constraint; DROP TABLE DEPT cascade constraint; DROP TABLE BONUS cascade constraint; DROP TABLE SALGRADE cascade constraint; DROP TABLE DUMMY cascade constraint;

CREATE TABLE EMP (EMPNO NUMBER(4) NOT NULL, ENAME VARCHAR2(10), JOB VARCHAR2(9), MGR NUMBER(4), HIREDATE DATE, SAL NUMBER(7,2), COMM NUMBER(7,2), DEPTNO NUMBER(2));

INSERT INTO EMP VALUES (1111,'SMITH','CLERK',7902,SYSDATE,800,NULL,20); INSERT INTO EMP VALUES (7499,'ALLEN','SALESMAN',7698,SYSDATE,1600,300,30); INSERT INTO EMP VALUES (7521,'WARD','SALESMAN',7698,SYSDATE,1250,500,30); INSERT INTO EMP VALUES (7566,'JONES','MANAGER',7839,SYSDATE,2975,NULL,20); INSERT INTO EMP VALUES (7654,'MARTIN','SALESMAN',7698,SYSDATE,1250,1400,30); INSERT INTO EMP VALUES (7698,'BLAKE','MANAGER',7839,'1-MAY-81',2850,NULL,30); INSERT INTO EMP VALUES (7782,'CLARK','MANAGER',7839,'9-JUN-81',2450,NULL,10); INSERT INTO EMP VALUES (7788,'SCOTT','ANALYST',7566,'09-DEC-82',3000,NULL,20); INSERT INTO EMP VALUES (7839,'KING','PRESIDENT',NULL,'17-NOV-81',5000,NULL,10); INSERT INTO EMP VALUES (7844,'TURNER','SALESMAN',7698,'8-SEP-81',1500,0,30); INSERT INTO EMP VALUES (7876,'ADAMS','CLERK',7788,'12-JAN-83',1100,NULL,20); INSERT INTO EMP VALUES (7900,'JAMES','CLERK',7698,SYSDATE,950,NULL,30); INSERT INTO EMP VALUES (7902,'FORD','ANALYST',7566,'3-DEC-81',3000,NULL,20); INSERT INTO EMP VALUES (7934,'MILLER','CLERK',7782,'23-JAN-82',1300,NULL,10);

CREATE TABLE DEPT (DEPTNO NUMBER(2), DNAME VARCHAR2(14), LOC VARCHAR2(13) );

INSERT INTO DEPT VALUES (10,'ACCOUNTING','NEW YORK'); INSERT INTO DEPT VALUES (20,'RESEARCH','DALLAS'); INSERT INTO DEPT VALUES (30,'SALES','CHICAGO'); INSERT INTO DEPT VALUES (40,'OPERATIONS','BOSTON');

CREATE TABLE BONUS ( ENAME VARCHAR2(10), JOB VARCHAR2(9), SAL NUMBER, COMM NUMBER );

CREATE TABLE SALGRADE ( GRADE NUMBER, LOSAL NUMBER, HISAL NUMBER );

INSERT INTO SALGRADE VALUES (1,700,1200); INSERT INTO SALGRADE VALUES (2,1201,1400); INSERT INTO SALGRADE VALUES (3,1401,2000); INSERT INTO SALGRADE VALUES (4,2001,3000); INSERT INTO SALGRADE VALUES (5,3001,9999);

CREATE TABLE DUMMY ( DUMMY NUMBER );

INSERT INTO DUMMY VALUES (0);

COMMIT;

SET TERMOUT ON PROMPT Demonstration table build is complete.

set feedback ON

--------------------------------------------------------------------------------------------------